The present invention relates to tools for building panels, and in particular, to a layout tool for use in establishing gable, hip/valley and radial cuts on large panel sheathing material.
In the construction of residential or commercial buildings, large planar sheets or materials, such as plywood or composites, are used for wall and roof sheathing. The panels are available in standard sizes, typically 4 feet in width and 8 foot in length. On site many of the panels can be installed without cutting. Where side walls merge with roof lines, i.e. gables, and adjoining roof sections intersect, i.e. hips and valleys, the panels must be cut to size for proper fitting and continuity.
The prevalent technique is for the worker to determine one length of the finished panel and determine the other length from standard tables. A fine is drawn between the markings and the panel cut accordingly. Similar techniques are used for both the wall panel and roofing panel layouts and cutting. The task is time consuming and prone to error, particularly for non-skilled workers.
In an effort to reduce the manual and cognitive aspects of large panel construction, a number of layout tools have been proposed. In one approach as disclosed in U.S. Pat. No. 6,199,288 to Gregory an elongated bar is provided with a first pin at a terminal end and a second pin slidable within an elongated slot. The second pin is referenced to pitch legends adjacent the slot to thereby establish the hypotenuse dimension and cutting line when the pins are positioned on opposite sides of the panel. Inasmuch as the width of the panel is variable in normal production, the pin-to-pin layout can result in incorrect layout inclinations. Also, the tool is usable only with full size panels, and does not assist in laying out end panels where the required cut is across less than the full panel width. A similar two-pin layout tool is disclosed in U.S. Pat. Nos. 6,266,889 and 6,147,797 to Boyce.
Other layout tools having capabilities for making beveled cuts have been directed toward dimensional lumber applications, such as rafter, joists, miters and the like 2X. Typical carpenter""s squares carrying pitch designations and tables, as disclosed in U.S. Pat. No. 1,196,519 to Caylor, provide at best short length markings that thereafter must be manually extended with supplemental straight edges for use with large panels. This presents the possibility of geometrically increasing errors in the initial layout when translated to larger panels. Similar difficulties are presented in the dimensional lumber layout tools as disclosed in U.S. Pat. Nos. 622,569 to Van Namee and 6,408,529 to Hodges.
The present invention provides a large panel sheathing tool for laying out beveled, transverse, and circular cuts for directly marking large building panels without the need for supplemental equipment. The sheathing tool comprises an elongated rectangular scale, having a length in excess of the width of a standard panel, carrying a T-bar disposed transverse to the front and rear surfaces thereof with a width the same as the width of the scale. The T-bar, in addition to accurately prescribing normal transverse cuts, provides a pair of pivot points when positioned against an edge of the panel. One surface of the scale includes indicia lines prescribing gable pitches referenced to one of the pivot points. When the designated pitch indicia is aligned with the opposite side of the panel an accurately positioned straight edge extends continuously across the panel for marking the desired cut. The other surface of the scale includes indicia lines referenced to the other pivot point and prescribes hip and valley pitches. The indicia lines extend across the surface and may also be used for making the desired layouts on partial panels. Additionally, the scale includes linear indicia for determining the pivot location for the cut as well as conventional measurements. The scale is further provided with a longitudinal series of holes referenced to the linear indicia and an integral pencil holder at the T-bar. The layout tool may be pivotally attached at a select hole of the desired radius and the scale rotated thereabout to layout circular cuts. Mirror image indicia may be provided for permitting direct layout of reverse inclinations on the panel. Thus, a unitary tool may be used for all the cuts required on large panel material, using continuous surfaces for marking and without the need for moving parts or supplemental equipment. The resultant simplicity and versatility increases productivity and allows lesser skilled workers to accurately layout and cut the large panels.
Accordingly, it is an object of the present invention to provide a tool for marking and making a variety of cuts in large sheathing panels.
Another object of the invention is to provide a layout tool for making gable, hip/valley, transverse, and radial cuts in roofing panels.
A further object of the invention is to provide a layout tool which reduces the time and skill level required to layout and cut large standardized standard size sheathing panels used in residential and commercial construction.